Groth16 verifier

This smart contract saves results of groth16 verifications.

Prerequisite

Ensure near-shell is installed by running:

near --version

If needed, install near-shell:

npm install near-shell -g

Clone repos and move to feature/alt_bn128 branches

git clone https://github.com/zeropoolnetwork/nearcore.git
cd nearcore
git checkout feature/alt_bn128
make build
cd ..

git clone https://github.com/zeropoolnetwork/near-sdk-rs.git
cd near-sdk-rs
git checkout feature/alt_bn128
cd ..

git clone https://github.com/zeropoolnetwork/near-groth16-verifier.git
cd near-groth16-verifier 

Building this contract

To make the build process compatible with multiple operating systems, the build process exists as a script in package.json. There are a number of special flags used to compile the smart contract into the wasm file. Run this command to build and place the wasm file in the res directory:

npm run build

Note: Instead of npm, users of yarn may run:

yarn build

Using this contract

Deploy to local net

Build and deploy this smart contract to a development account. This development account will be created automatically and is not intended to be permanent. Please see the "Standard deploy" section for creating a more personalized account to deploy to.

nearup localnet --binary-path ../nearcore/target/release --overwrite 

ln -s ~/.near/localnet/node0/validator_key.json  ~/.near/validator_key.json

export NEAR_ENV=local
near dev-deploy --wasmFile res/near_groth16_verifier.wasm --masterAccount node0

Behind the scenes, this is creating an account and deploying a contract to it. On the console, notice a message like:

Done deploying to dev-1234567890123

In this instance, the account is dev-1234567890123. A file has been created containing the key to the account, located at neardev/dev-account. To make the next few steps easier, we're going to set an environment variable containing this development account id and use that when copy/pasting commands. Run this command to the environment variable:

source neardev/dev-account.env

You can tell if the environment variable is set correctly if your command line prints the account name after this command:

echo $CONTRACT_NAME

The next command will call the contract's groth16verify_log method:

near call $CONTRACT_NAME groth16verify_log '{"vk":"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","proof":"Qexag8d0jvm1IWZywscRBuvdSEvlGuhvVg5Qj97vhS5VFas06bgj/yXiuZ+yJ/WZWCYDYq8e5HZPITpoaHAvGckDPBplyUtn8zZ3UI4f5E1uLmxlehAkzVK33Fp8/SEZX4v8OLLT3MP/FWhDvS43u2sLvZcCstjVjbarImuLiSA0IW7UmNgG7u8x99JExO0pp0EAGJ3PiBOzyZ/PhxUPBXvOgxhwNzx0nzZzp+aSY8yhsWxFWRl6UWzmS6J/ieUS1q5Tjwq9gs4qcX6+Q9WWRpvYVboY+f4d6smQyryKdB5Hi5E8/jWGPoD9tFJDN4KVnnESrKi7fVjH6A3twUaQEw==","input":"AwAAAMI1CN4U9DnKW3soxArLClszrtTa/MGicksQVWpir/QNW/hp3N50wmjr1CUHvGP6u6WnrdK7oRDtSHgjcjmUVyr8NQtA06gcVk9m3KPdmWele0Bx9AcLpToixRb2FCx/JQ=="}' --accountId $CONTRACT_NAME

This data corresponds to withdrawal proof for simple mixer. Serialization from ethereum JSON to base64 is described at the test.

To retrieve the result of 1st call to the contract, call get_call with the following:

near view $CONTRACT_NAME get_call '{"n":0}'

You should get true as a result.

Testing

To test run:

cargo test -- --nocapture